I'm with hyacinth, I can't stand the amount of sugar in the fruit juice you can buy in bottles etc. The link she posted explains it well.
Personally I drink water, roughly 4-5L per day, sometimes a can of pepsi max, if I feel like something different. Other than that I might have a coffee with no sugar (or sweetner either) but no flavoured milks or fruit juice in our house. Occassionally I give the other half V8 veggie juice but that's as far as we go.